Today we move on from the Everest base camp and make our way to the base camp at Cho Oyu, the world’s sixth highest mountain.

During a journey over mainly dirt roads we come across a Tibetan family grazing their yaks while, close by, we get a glimpse of a vulture close to a dead yak. We set up camp on arrival at an altitude of 4911 metres and start to get to know the terrain we will cover over the following days.

Our reconnaissance work enables us to recognize the peaks for our repeat photography exercise, and allows us to prepare for the difficulties we will face in reaching them. Apart from the high altitude, which we are now used to, we also need to deal with the fact that crossing the Gyarag Glacier is not without its challenges due to a collapse in the central area, but we have no choice but to traverse that part if we are to scale the face of the foresummit of Mount Jobo Rabzang (6666 metres), from where Major E.O. Wheeler took a panoramic shot of the glacier during his expedition in 1921. To complicate things even more, when we reach the last checkpoint at over 5400 metres the border guard on duty refuses to let our porters come with us as they are Tibetan. This is because the Gyarag Glacier lies only a few kilometres from the Nangpa La Pass, now under close observation by the Chinese military to discourage illegal immigration by Tibetans who are constantly trying to reach Nepal, now the residence of the Dalai Lama.

Eventually we reach our first location, which is less complicated and lies on the water basin side of the Gyarag Glacier. Here we take “repeat photographs” which clearly highlight the glacier’s loss of ice mass. The next morning we take a recently reconstructed road that enables us to get reasonably close to our first location. Thanks to having consulted Google Earth before leaving I manage to recognize a potential spot from where I can shoot the photograph and we manage to reach it fairly easily.

The next day the weather gets bad so, while Andrea uses GPS mapping techniques to measure Gyarag’s old glacial front, I decide to gather GPS readings of other spots. This will enable us to determine the shortest route to the crest of a mountain located above the Gyarag glacial front at an altitude of some 5700 metres, the setting for some key shots.

The next day we get up at dawn and make our way by truck to the start of our ascent. The high altitude makes progress towards the summit laborious as we start work on calculating the exact spot from where Major E.O. Wheeler took his photograph. The task is far from easy as the crest of the mountain is enormous, and archive photographs offer few if any distinguishing features. After going up and down several times I manage to identify the spot thanks to large boulders and part of the crest of the mountain that towers above the glacial moraine, all visible on the archive photograph. The cold is biting and I have to wear gloves, which slows down the task of mounting the camera. Everything is ready for the shot, the exposure readings taken, but the time is not yet ripe given that the shadows do not match those of the archive photograph. I just need to be patient for another hour. After all, photography requires precise timing that needs to be rigorously respected, especially if we want to achieve a precise outcome of scientific value. The purpose of our project is such that there is no margin for error.

The expedition is drawing to an end. Unfortunately, we are not able to come to an agreement with the tour operator regarding our request to stay for a few more days at the Cho Oyu base camp to make up for the days lost on Everest. As a consequence, with no time to recoup energy, we are obliged to make plans to descend the Gyarag Glacier the following day to measure the face of the glacier sitting above the glacial lake. The following day Andrea and I choose what seems to be the least dangerous route to descend the steep shingle-covered side of the moraine slope of the Gyarag Glacier. We are in fact on a slope that is continuously in movement with frequent rock falls. To avoid being struck by a falling boulder there is only one solution: to get moving, and fast.

Once we manage to get onto the glacier Andrea takes GPS readings to plot our path and after about twenty minutes we reach the source of the cascade of water, an enormous ice cavern (at approximately 5130 metres) where most of the melt water from the glacier merges. This is an extraordinary sight and the grotto looks like a wound from which water, the life-blood of the glacier, is pouring out.

After passing the cascade, leaping from boulder to boulder, I switch off the GPS after checking the last extremities of the active moraine from the Gyarag Glacier. And so we begin our journey downstream, constantly in radio contact with our guide. Climbing up the lateral moraine on our right is far too risky, so we decide to walk around the enormous lake (over two kilometres in length and 600 metres wide), covering a distance of over three kilometres with the constant threat of boulders crashing down on us, which is quite a frightening experience. As time passes I feel my energy levels begin to drop and a sense of exhaustion sets in. In the meantime the night begins to draw in and we start looking for a way out. We manage to follow a track that takes us north and to then climb the lateral moraine on the right until we reach the road and the van where our guide and driver are waiting to take us back to the base camp.

With this last effort we have finished our final high-altitude fieldwork and there follows two days of spectacular travel between Tibet and Nepal, enjoying for one more time the air, colours and landscapes that change continuously along the road that takes us back to Kathmandu.